Title : Fruit Tree Physiology

Authors : W.S. Dhillon and Z.A. Bhat

PAU, Ludhiana -141004, India

Pages : 309

Publisher : Narendra Publishing House
Delhi -110006, India

Tree physiology is a difficult and challenging area for
working. Knowledge on physiology of growth and
development of fruit tree is essential for a horticulture
researcher/teacher. Even though many books on tree
physiology are available, books on fruit tree physiology are
rare to find except for a few edited books on the physiology
of fruit trees. However, these books are relatively old ones
and no text books are available for researchers, teachers
and students working in the area of fruit crops. In this regard,
the book entitled “Fruit Tree Physiology” authored by Drs.
W.S.Dhillon and Z.A.Bhat is timely and very informative
for horticulturists as well as physiologists who are working
on fruit crops.

This book consists of 12 chapters which include, bud
dormancy, chilling requirement  in fruit crops, heat units and
thermoperiodism, physiology of flowering in horticultural
crops, fruit growth  and development, unfruitfulness in fruit
crops-causes and control measures, alternate bearing in fruit
plants-causes and management, parthenocarpy-A
mechanism for seedlessness, graft incompatibility- causes
and remedial measures, physiology of dwarfism in fruit
plants, fruit ripening- biochemistry, physiology and regulation
and abscission in fruit plants.

Bud dormancy chapter includes the classification of
dormancy, site of dormancy, physiological and molecular
basis of dormancy, factors affecting and methods to
overcome dormancy.

Chilling requirement in fruit crops chapter has covered
various crops which require chilling temperatures for
flowering. It includes various aspects of chilling like
importance of chilling,, length of chilling requirement in fruit
species, resting phase, effective chilling temperatures, effect

Book Review

of high temperatures on the chilling requirement, models
for fruit trees etc.

Heat Units and thermoperiodism chapter explains the
degree days concept, heat requirement in fruit various crops
like apple, grapes, date palm, mango, plum, citrus, raspberry,
peach, apricot, banana, pineapple and olive. This chapter
also deals with thermoperiodism in fruit crops. The chapter
is useful to understand the temperature requirement for
different phonological events in fruit crops and their
modeling.

Physiology of flowering in horticultural crops: This
chapter deals with the one of the most complex
developmental process in fruit crops called flowering.
Flowering chapter covers many interesting aspects like
photoperiodism, phytochromes, radiation experiments to
show the importance of phytochromes in flowering, hormonal
balance, florigen concept, vernalisation, and molecular
aspects of flowering. Authors have highlighted many papers
which deal with the identification of genes, transcription
factors associated with flowering.

Fruit growth and development chapter has covered the
pattern of fruit growth in many fruit crops and the factors
associated with fruit growth.

Unfruitfulness in fruit crops-causes and control
measures. Influence of many environmental factors, light,
temperature, rainfall, wind, humidity, tree age, soil nutritional
status, horticultural practices like pruning, grafting, etc have
been explained in this chapter. Alternate bearing in fruit crops
and its causes and control measures is also explained with
respect to endogenous and exogenous factors.

Mechanism of parthenocarpy, factors affecting
parthenocarpy, genetics of parthenocarpy, physiology of
parthenocarpy and induction of parthenocarpy in fruit crops
is explained in a simple and more understandable way.

Graft incompatibility-causes and remedial measures
chapter include classification of incompatibility, structural
or anatomical basis, biochemical basis and other



microorganism basis has been explained neatly in this chapter.
Various methods to detect incompatible combinations have
also been given in this chapter. This will be useful for
students as well as researchers.

Along with graft incompatibility, dwarfism is also very
important in fruit crops. Dwarf plants are highly preferred
in all the fruit crops especially for the high density orcharding.
This chapter deals with physiology of dwarfism, use of root
stocks, interstocks, bioregulators, pruning and training,
phenols. Use of girdling, scoring, bark inversion, root pruning,
and paclobutrazol is also highlighted in this chapter. Use of
biotechnology to induce dwarfness in apple is briefly
explained. Available dwarfing root stocks have also been
given for different fruit crops like cherry, apple, mango, plum,
pear, peach, guava and ber.

Fruit ripening chapter gives only brief account of
biochemical events. It covered climacteric and non-
climacteric fruits, mechanism of ripening, ethylene
biosynthesis, chlorophyll degradation, starch hydrolysis, cell
wall degradation etc. Regulation off ripening by controlled
atmosphere storage, chemical usage, MCP and bioregulators
is also briefly covered in this chapter. However, for
biochemistry of ripening still books by Hulme is the best.

Last chapter of the book is abscission in fruit plants.
This chapter deals with morphological and anatomical and
biochemical changes, formation of abscission zones,
significance of abscission zones, control of abscission. It
has also touched briefly the factors affecting the abscission.

K.S.Shivashankara
Principal Scientist

Division of Plant Physiology and Biochemistry
 Indian Institute of Horticultural Research

Hessaraghatta lake post, Bangalore – 560 089